diff --git a/Classes/smcWrapper.m b/Classes/smcWrapper.m
index b1fd4eb..6b87272 100755
--- a/Classes/smcWrapper.m
+++ b/Classes/smcWrapper.m
@@ -131,7 +131,7 @@ NSArray *allSensors;
 	UInt32Char_t  key;
 	SMCVal_t      val;
 	//kern_return_t result;
-	sprintf(key, "F%dAc", fan_number);
+	sprintf(key, "F%cAc", fannum[fan_number]);
 	SMCReadKey2(key, &val,conn);
 	int running= [self convertToNumber:val];
 	return running;
@@ -153,7 +153,7 @@ NSArray *allSensors;
 	//kern_return_t result;
 	NSMutableString *desc;
 
-    sprintf(key, "F%dID", fan_number);
+    sprintf(key, "F%cID", fannum[fan_number]);
     SMCReadKey2(key, &val,conn);
 
     if(val.dataSize>0){
@@ -178,7 +178,7 @@ NSArray *allSensors;
 	UInt32Char_t  key;
 	SMCVal_t      val;
 	//kern_return_t result;
-	sprintf(key, "F%dMn", fan_number);
+	sprintf(key, "F%cMn", fannum[fan_number]);
 	SMCReadKey2(key, &val,conn);
 	int min= [self convertToNumber:val];
 	return min;
@@ -188,7 +188,7 @@ NSArray *allSensors;
 	UInt32Char_t  key;
 	SMCVal_t      val;
 	//kern_return_t result;
-	sprintf(key, "F%dMx", fan_number);
+	sprintf(key, "F%cMx", fannum[fan_number]);
 	SMCReadKey2(key, &val,conn);
 	int max= [self convertToNumber:val];
 	return max;
diff --git a/smc-command/smc.c b/smc-command/smc.c
index f023e6e..379c71d 100755
--- a/smc-command/smc.c
+++ b/smc-command/smc.c
@@ -557,24 +557,24 @@ kern_return_t SMCPrintFans(void)
     for (i = 0; i < totalFans; i++)
     {
         printf("\nFan #%d:\n", i);
-        sprintf(key, "F%dID", i);
+        sprintf(key, "F%cID", fannum[i]);
         SMCReadKey(key, &val);
         if(val.dataSize > 0) {
             printf("    Fan ID       : %s\n", val.bytes+4);
         }
-        sprintf(key, "F%dAc", i);
+        sprintf(key, "F%cAc", fannum[i]);
         SMCReadKey(key, &val);
         printf("    Actual speed : %.0f\n", getFloatFromVal(val));
-        sprintf(key, "F%dMn", i);
+        sprintf(key, "F%cMn", fannum[i]);
         SMCReadKey(key, &val);
         printf("    Minimum speed: %.0f\n", getFloatFromVal(val));
-        sprintf(key, "F%dMx", i);
+        sprintf(key, "F%cMx", fannum[i]);
         SMCReadKey(key, &val);
         printf("    Maximum speed: %.0f\n", getFloatFromVal(val));
-        sprintf(key, "F%dSf", i);
+        sprintf(key, "F%cSf", fannum[i]);
         SMCReadKey(key, &val);
         printf("    Safe speed   : %.0f\n", getFloatFromVal(val));
-        sprintf(key, "F%dTg", i);
+        sprintf(key, "F%cTg", fannum[i]);
         SMCReadKey(key, &val);
         printf("    Target speed : %.0f\n", getFloatFromVal(val));
         SMCReadKey("FS! ", &val);
diff --git a/smc-command/smc.h b/smc-command/smc.h
index 1d06415..34e17aa 100755
--- a/smc-command/smc.h
+++ b/smc-command/smc.h
@@ -98,6 +98,8 @@ typedef struct {
 
 typedef unsigned char              SMCBytes_t[32];
 
+UInt8 fannum[] = "0123456789ABCDEFGHIJ";
+
 typedef struct {
   UInt32                  key; 
   SMCKeyData_vers_t       vers;